This invention relates generally to air flow damper mechanisms, and, more particularly, to air flow damper mechanisms for use in refrigeration systems.
Conventionally, multi-compartment refrigerators include a fresh food compartment and a freezer compartment for chilling and preserving food items at respective desired temperatures. Typically, the fresh food compartment is set to a user adjustable setting, and the fresh food compartment is thermostatically controlled to energize a refrigeration circuit (i.e., evaporator, condenser, etc.) to generate cooled air for introduction into the fresh food compartment to maintain the fresh food compartment at specified temperature levels. When the refrigeration circuit is energized, evaporator air is also introduced into the freezer compartment, and the temperature of the freezer compartment is controlled according to a user adjustable damper located in a flow path between the fresh food compartment and the freezer compartment. When the damper is fully closed, air flow from the freezer compartment into the fresh food compartment is substantially prevented, thereby maintaining the cooled evaporator air in the freezer compartment and lowering the freezer compartment temperature. When the damper is fully open, an appreciable amount of air from the freezer compartment flows into the fresh food compartment from the freezer compartment, thereby increasing the temperature of the freezer compartment. Of course, air flow from the freezer compartment to the fresh food compartment affects the frequency at which the refrigeration circuit is energized to maintain the fresh food compartment temperature at a desired temperature.
Typically, the damper is a pivoting plate or baffle located in a duct extending between the fresh food compartment and the freezer compartment. See, for example, U.S. Pat. No. 5,901,562. The plate pivots about an axis in the plane of the plate to obstruct or clear an air flow path through the duct. Conventionally, the damper is moved from a fully closed position to a fully opened position in about a 90xc2x0 pivot of the plate. As the plate pivots, the area of the passage opened or closed varies approximately sinusoidally. In other words, small changes in damper position can result in large changes in the flow path area in certain positions of the damper, while in other positions of the damper, relatively large changes in position result in almost negligible changes in the flow path area. As such, it is difficult to precisely control the position of the damper to achieve a desired effect, despite sophisticated controls and complex mechanical linkages to position the damper plate.
In one aspect, an air flow damper assembly is provided. The assembly comprises a duct member comprising a first air flow opening therethrough, and a damper disposed within said duct member and comprising a substantially cylindrical rim for regulating air flow through said first opening.
In another aspect, an air flow assembly for a refrigerator including a fresh food compartment and a freezer compartment is provided. The damper assembly comprises a duct portion comprising a first air flow opening therethrough and adapted for flow communication between the fresh food compartment and the freezer compartment, and a damper in flow communication with said duct portion. The damper comprises a shaft and a substantially cylindrical rim extending radially from said shaft, and the rim is positionable with respect to said opening by rotating said shaft to regulate air flow through said first opening.
In yet another aspect, a refrigerator is provided. The refrigerator comprises a freezer compartment, a fresh food compartment, and an air flow assembly. The air flow assembly comprises a duct portion in flow communication with said freezer compartment and said fresh food compartment, and a damper comprising a longitudinal axis and a radially extending rim rotatable about said longitudinal axis.
In still another aspect, a refrigerator is provided. The refrigerator comprises a freezer compartment, a fresh food compartment, a mullion separating said freezer compartment and said fresh food compartment, and a duct member establishing flow communication between said freezer compartment and said fresh food compartment. The duct member comprises a substantially cylindrical opening accessible to said freezer compartment, and a damper assembly is located in said cylindrical opening and comprises a shaft and a rim radially extending from said shaft. The rim is tapered to obstruct varying portions of said opening as said shaft is rotated.